They've done maps, weapons and hats.
I'm betting an official update page tonight - update tomorrow (preferably before the Summer Sale hits).
Does...does the import tool support weapons?
...Because last I checked it didn't, which would mean we're getting 64 more loving hats
They'd better throw some weapons in there
At this point griefblower and the reaper are really likely. Also if this is the lecture valley update (and with all the bread it's very likely) I'd also suggest we might be getting a new engi pda with catapult.
Of course these aren't confirmed - but keep your fingers crossed. ^.^
Honestly - some of the old weapons might change so drastically they feel like new weapons haha.
EDIT: Also the mystery card changed again.

Looks like those Summer Claim Checks are tied in with the entire deal - maybe the Summer Sale is focused on different places different days and the notion of going on holiday - so the TF2 mercs joined in but now need their luggage back, then the checks give you a random piece of the merc's luggage that can only be opened with a special.. key.